1. Field of the Invention
This invention relates generally to computer board/circuit development boards, and more specifically to a PCMCIA bus-compatible extender card adapted to permit the development of PCMCIA boards on the target notebook, laptop, palmtop, pen-based, or similar computing system.
2. Description of Related Art
Bus extender cards are generally well known in the board/circuit development art. An extender card generally does not provide any processing or programming capability, and serves simply to provide a more convenient access to a host computer's bus than is otherwise available.
Recent advances in notebook computers have precipitated the development of the Personal Computer Memory Card International Association (PCMCIA) bus standard. Recently, developers have realized that the PCMCIA bus can advantageously be used to connect a wide variety of peripheral devices, and not merely memory cards, to computers.
Due to the typically large size of prototype boards as compared to their subsequent and corresponding final design boards, it is difficult to develop prototype boards within the confines of a computer. The necessarily cramped space within a notebook computer makes it even more difficult to do notebook computer board development.
FIG. 1 illustrates the present state of the art in PCMCIA board development. A full-sized personal computer (PC) 10 is used, rather than a notebook computer. The PC provides a much larger internal board space 12 within which to work. The PC is provided with one or more bus slots 14, which provide access to the PC's AT bus. Conventional PCs do not have a PCMCIA bus, however, and are used only as a cross-development platform for PCMCIA cards intended for ultimate use on another host platform such as a notebook computer having a PCMCIA bus.
In order to perform development of PCMCIA bus-compatible boards 16, therefore, the present state of the art provides an AT bus card 18 which has an interface for connection to the AT bus and one or more interfaces for connection to the PCMCIA board. As illustrated, the PCMCIA board may be directly coupled to the AT card, in which case the top cover of the PC must be removed, as the PCMCIA board will extend too far in the vertical plane. As also illustrated, the PCMCIA board may optionally be coupled to the AT card via a ribbon cable 20 or other suitable means, in which case an opening must be provided through the PC case, to allow extension of the cable. Optionally, the AT card may provide a PCMCIA port 22 on the conventional rear panel at which access if generally had to slot cards, and the ribbon cable 20 may be coupled to this port 22.
It is believed that such AT cards are currently available from Intel Corporation. It will be understood that this prior system has at least two significant disadvantages which render it less than suitable for notebook computer PCMCIA card development. First, the AT card cannot be used in conjunction with the notebook computer itself. Thus, the developer cannot be certain during development that the PCMCIA card will actually work in a notebook computer, as the development platform (PC) and the target platform (notebook) may have unpredictably different bus, timing, loading, and other characteristics, even among so-called "compatible" components and protocols. Second, the AT card does not provide any readily-accessible means for "wirewrapping" components to form the desired circuitry. Board development generally is performed using at least some degree of wirewrapping, which provide for easy reworking of circuit configuration, in case the designer has made an error or oversight in the circuit layout.
Thus, it is seen that it is highly desirable to have a PCMCIA extender card which solves the problems detailed above. The PCMCIA extender card should provide direct access to a notebook computer such that the target platform notebook computer can be directly utilized as the development platform, to ensure board compatibility and to eliminate the unnecessary expense otherwise required in purchasing a PC development platform. Further, the PCMCIA extender card should provide wirewrap access to all pinouts of the PCMCIA bus, to enable the developer to readily reconfigure the circuit under design, and to provide convenient test probe access to the bus.